The present invention relates to a plastic clip which comprises a pin, and a bush adapted to receive the pin therein and allow an outer diameter thereof to be expanded by pushing the pin into the bush, and more specifically to a plastic clip suitable for coupling an attachment component to a workpiece, such as a panel of an automobile body.
There has been known a plastic clip comprising a pin, and a bush having a hollow portion formed to receive the pin therein, wherein the pin has a shape formed to be received into the hollow portion of the bush and axially moved from a non-fastened position, causing no expansion in an outer diameter of the bush, to a fastened position, causing an expansion in the outer diameter of the bush by a pushing operation. For example, Japanese Utility Model Laid-open Publication No 63-003513 (Patent Document 1) discloses a clip of the above type. This clip is designed such that, when a large-diameter portion of a pin is inserted into a bush by a pushing operation, a peripheral wall of the bush is expanded in a radially outward direction of the bush to allow a workpiece and an attachment component to be clamped between the expanded portion and a flange of the bush, so as to achieve a coupling between the workpiece and the attachment component. The clip disclosed in Patent Document 1 is designed to cope with an increase in total thickness of a workpiece and an attachment component to be coupled together, and to allow the pin to be moved within the bush from a fastened position to a non-fastened position, so as to facilitate detaching the clip.
Japanese Patent Laid-Open Publication No. 11-153113A (Patent Document 2) discloses another clip which comprises a bush having a peripheral wall formed with a large opening and a hollow portion formed along an axis thereof, and a pin having a head formed in a particular shape to serve as an expanding portion. When the expanding portion at the head of the pin is inserted into the bush by a pushing operation, the peripheral wall with the opening is expanded in a radially outward direction of the bush to allow a workpiece and an attachment component to be clamped between the expanded portion and a flange of the bush, so as to achieve a coupling between the workpiece and the attachment component. The clip disclosed in the Patent Document 2 is designed to allow the bush to be largely expanded so as to cope with an increase in diameter of a mounting hole.
Japanese Patent Laid-Open No. 2003-343528A (Patent Document 3) discloses yet another clip which comprises a bush having a peripheral wall formed to be partially cut off and a hollow portion formed along an axis thereof, and a pin adapted to be inserted into the hollow portion. When the pin is inserted into the bush by a pushing operation, the peripheral wall is expanded around the cutoff in a radially outward direction of the bush to allow a workpiece and an attachment component to be clamped between the expanded portion and a flange of the bush, so as to achieve a coupling between the workpiece and the attachment component.
The clip disclosed in Patent Document 1 is designed to expand an outer diameter of the bush over the entire longitudinal length of the bush, so as to cope with an increase in total thickness of a workpiece and an attachment component to be coupled together. Thus, it is necessary to have a relatively long bush, which is unfavorable in a situation where a fastened position has to be set in a narrow range in the longitudinal direction. In the clip disclosed in the Patent Document 2, the pin has the head formed in a particular shape, increasing the cost of forming the pin. Moreover, the pin and the bush in the clip disclosed in the Patent Document 2 are not designed to be pre-assembled to one another, and therefore a fastening operation has to be performed while paying attention to preventing the pin and the bush from separating from one another, resulting in poor operating efficiency. Further, as with the clip disclosed in Patent Document 1, this clip is designed to expand an outer diameter of the bush over the entire longitudinal length of the bush, and therefore it is necessary to have a relatively long bush, which is unfavorable in the situation where the fastened position has to be set in a narrow range in the longitudinal direction. The clip disclosed in the Patent Document 3 is not designed to largely and reliably expand an intended portion of the bush, and therefore deterioration in coupling force between the workpiece and the attachment component is likely. Moreover, due to difficulty in reliably expanding an intended portion of the bush, the clip disclosed in Patent Document 3 is required to have a relatively long bush, which is unfavorable in the situation where the fastened position has to be set in a narrow range in the longitudinal direction.